Sadly enough, serious violent crime started rising in Britain after it enacted legislation banning weapons for personal self-defense. Is the Happy Slapping phenomenon indicative of a society that has eliminated repercussions for assaults and criminals?  In Britain, the rise in rapes, assaults, robbery assaults, etc., has risen dramatically so that Britain has a much higher crime rate than America in many categories. Here's an article: "An Englishman's home is his dungeon" By Mark Steyn.

Weapons for personal self-defense in the home has a deterrent effect. The criminal hestitates before acting, taking into consideration their own personal safety. Even if a person doesn't care to own a weapon, the DETERRENCE OF NOT KNOWING stops a perpetrator from commiting the crime.

In Britain, people cannot possess weapons for self-defense so hot burglaries - where the criminal KNOWS the victim is home - are tragically high. These are 'hot burglaries'. And if you don't have any money for criminals or junkies, what is left but your person, your life or your family. Does gun ownership deter "Hot" burglaries? In studies involving interviews of felons, one of the reasons the majority of burglars try to avoid occupied homes is the chance of getting shot. (Increasing the odds of arrest is another.) A study of Pennsylvania burglary inmates reported that many burglars refrain from late-night burglaries because it's hard to tell if anyone is home, several explaining "That's the way to get shot." (Rengert G. and Wasilchick J., Suburban Burglary: A Time and a Place for Everything, 1985, Springfield, IL: Charles Thomas.)

By comparing criminal victimization surveys from Britain and the Netherlands (countries having low levels of gun ownership) with the U.S., Florida State University criminologist Gary Kleck determined that if the U.S. were to have similar rates of "hot" burglaries as these other nations, there would be more than 450,000 additional burglaries per year where the victim was threatened or assaulted. (Britain and the Netherlands have a "hot" burglary rate near 45% versus just under 13% for the U.S., and in the U.S. a victim is threatened or attacked 30% of the time during a "hot" burglary.) Source: Gary Kleck, Targeting Guns: Firearms and Their Control, Walter de Gruyter, Inc., New York, 1997.